Wire stripper

ABSTRACT

A wire stripper comprising a pair of pivoted arms with hand grips at one end, one arm carrying fixed and movable clamps with outer wire gripping jaws. The clamps are resilient to accommodate different wire sizes. A hairpin-shaped spring between the clamps carries a pair of stripping knives. A cam connected to the movable clamp is actuated by the first stage of hand grip squeezing movement to close the jaws and knives, the second stage of squeezing movement retracting the knives to strip the insulation from the wire. In the third and last stage of squeezing movement the cam releases the jaws and knives, a spring returning the parts to their original position.

United States Patent 1 Mugnier WIRE STRIPPER [75] Inventor:

[73] Assignee: Utica Tool Company, Inc.,

Orangeburg, SC.

[22] Filed: Jan. 5, 1972 [21] Appl. No.: 215,501

Lucien Mugliier, Nice, France [30] Foreign Application Priority Data Jan. 6, 1971 France 7101042 [521 [1.8. CI 8l/9.5 A [51] Int. Cl H02g 1/12 [58] Field of Search 81/95 A, 9.5 R

[56] References Cited UNITED STATES PATENTS 2,601,797 7/1952 Holt, Jr 81/95 A 3,087,363 4/1963 Jacobs 81/95 A 3,125,908 3/1964 Rozmus 8l/9.5 A

FOREIGN PATENTS OR APPLICATIONS 1,164,184 9/1969 Great Britain 81/95 A 51 Dec. 4, 1973 Primary ExaminerDona1d G. Kelly Assistant Examiner-Roscoe V. Parker AttorneyJ. King Harness et al.

[57] ABSTRACT A wire stripper comprising a pair of pivoted arms with hand grips at one end, one arm carrying fixed and movable clamps with outer wire gripping jaws. The clamps are resilient to accommodate different wire sizes. A hairpin-shaped spring between the clamps carries a pair of stripping knives. A carn connected to the movable clamp is actuated 'by the first stage of hand grip squeezing movement to close the jaws and knives,

the second stage of squeezing movement retracting the knives to strip the insulation from the wire. In the third and last stage of squeezing movement the cam releases the jaws and knives, a spring returning the parts to their original position.

I 14 Claims, 1 Drawing Figure WIRE STRIPPER BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to wire strippers and particularly hand tools for gripping, stripping and releasing insulated wires of different diameters without adjustment.

2. Description of the Prior Art Known prior patents in this area include the following: US. Pat. Nos. Holt 2,601,727; Rozmus 3,125,908; Rozmus 3,343,433; Rozmus 3,580,114.

These prior wire strippers have various disadvantages which it is an object of the present invention to overcome. Among other drawbacks of the abovementioned constructions are the fact that in some cases they are cumbersome and expensive to constructjand are not easily adjustable for difierent wire diameters. In constructions where the wire is released after the stripping operation and during return of the hand grips, the danger exists that untimely return of the knives may crush or otherwise damage the stripped wire. Another is fixed to and extends from the outer end of arm 12. A toothed wire jaw 22 is formed at the outer end of clamp 21.

A movable clamp 23 is pivoted at 24 to arm 12 inwardly of fixed clamp 21 and carries a toothed wire gripping jaw 25 at the outer end thereof, facing jaw 22.

, Clamps 21 and 23 are preferably constructed of steel J 31 which rests in recess 27 of cam 26 when the parts are in their normal open position as shown in the FIG- URE. When hand grips 15 and 16 are squeezed, however, roller 31 will ride up onto ramp 28, causing clamp 23 to rock clockwise about pivot 24 toward fixed clamp disadvantage of certain prior art constructions is their inability to strip relatively long lengths of wire such as are used in solderless connections.

BRIEF SUMMARY OF THE INVENTION 3 The present invention has as an object the provision of a relatively compact, simple and inexpensively manufactured wire stripper in which it is unnecessary to I make any adjustments to accommodate different wire diameters. It is a further object to provide such a wire stripper in which it is inherently impossible to crush or otherwise damage the wire after the stripping operation, and in which relatively long' lengths of wire may be stripped.

It is a further object to provide such a wire stripper in which the stripping knives may be replaced rapidly and without the necessity of disassembling the tool.

Briefly, the invention comprises a pair of pivoted arms having hand grips at one end, one of the arms carrying fixed and movable clamps with wiregripping jaws A hairpin-shaped spring 32 is disposed between clamps 21 and 23, the bight 33 of this spring being adjacent the outer end of arm 13 where it is retained between lugs 34 and 35 carried by this arm. The outer ends of spring 32 carry facing grooved knives 36 and 37 extending inwardly from jaws 22 and 25 and adapted to penetrate and then strip the insulative sheath of a wire. The degree to which the knives apat their outer ends. The clamps are resilient to accommodate different wire sizes. A pair of knives are movable in response to closing clamp movement to penetrate the insulative sheath of the wire. The clamps and knives are actuated by squeezing the'hand grips. In a first stage of movement, the jaws and knives close, in a second stage the knives are drawn axially to strip the wire, and in the third and final squeezing stage both the jaws and knives are released. Release of the hand grips returns all parts to their original positions.

BRIEF DESCRIPTION OF THE DRAWINGS In the Drawing, the FIGURE is a side elevational view of the wire stripper shown in its open position.

DESCRIPTION OF THE PREFERRED EMBODIMENT The wire stripper is generally indicated at 11 and comprises a pair of arms 12 and 13 pivotedly connected at 14 and having handgrips 15 and 16 respectherefore spreading apart grips 15 and 16. A clamp 21 proach each other during the cutting operation will be a function of the final spacing between the toothed jaws. Spring 32 is retained in position by a tab 38 on clamp 23.

In operation, the wire to be stripped will be placed between jaws 22 and 25 and knives 36 and 37, with its end opposite the graduated mark 39 on clamp 21 corresponding to the length to be stripped. During the first stage of movement when grips 15 and 16 are squeezed, roller 31 will ride up the slope of recess 27, moving away from pivot 24 and causing rotation of movable clamp 23. Jaws 22 and 25 will squeeze the wire between them, clamps 21 .and 23 deforming if necessary to accommodate larger wire diameters. Spring 32 will partially close under the pressure of the two clamps and its knives will penetrate the insulative sheath of the wire to a degree controlled by the spacing of jaws 22 and 25. Lug 34 will engage the bight of spring 32.

During the second stage of movement, roller 31 will roll over the portion 28 of the cam and jaws 22 and 25 will remain closed while lug 34 retracts spring 32 which strips ofl' the insulation from the wire. In the third and final stage of movement of the arms, roller 31 will drop into recess 29 of cam 26 and clamps 21 and 23 will separate due to the force of spring 32, causing both jaws 22 and 25 and knives 36 and 37 to release the wire. Upon release of hand grips 15 and 16, the arms will retract to their former position under the influence of spring 19, spring 32 being returned by lug 35.

Y I claim:

1. A wire stripper comprisinga pair of pivoted arms having hand grips at one end, a movable and afixed clamp mounted on a first of said arms, means carried by said arms responsive to squeezing of said hand grips to move said movable clamp toward said fixed clamp, wire gripping jaws carried by the outer ends of said clamps, a pair of knives disposed inwardly of said jaws, said knives being movable in response to said clamp movement from a retracted position to a position penetrating the wire insulation, the degree to which the knives come together being a function of the spacing of said jaws when they grip the wire, said clamps being made of material which is sufficiently resilient to accommodate different wire diameters and being deformable in response to gripping of the wire insulation by said clamps and further squeezing of the hand grips.

2. A wire stripper comprising a pair of pivoted arms having hand grips at one end, a movable and a fixed clamp mounted on a first of said arms, means carried by said arms responsive to squeezing of said hand grips to move said movable clamp toward said fixed clamp, wire gripping jaws carried by the outer ends of said clamps, a pair of knives disposed inwardly of said jaws, said knives being movable in response to said clamp movement from a retracted position to a position penetrating the wire insulation, the degree to which the knives come together being a function of the spacing of said jaws when they grip the wire, said clamps being made of material which is sufl'rciently resilient to accomodate different wire diameters, said means for moving the movable clamp comprising a cam carried by one of the arms and a cam actuating element carried by the other arm, said cam being shaped so that a first stage of squeezing movement of said hand gripswill cause said movable clamp to move toward the fixed clamp, means on said second arm responsive/to a second stage of squeezing movement to draw said knives away from said jaws, thereby stripping said insulation from the wire, said cam being so shaped that the jaws and knives will be prevented from opening during said second squeezing stage.

3. The combination according to claim 2, said cam being so shaped that as said handles are squeezed beyond said second stage of movement said jaws will be released, said knives comprising the facing ends of a hairpin-shaped spring between said jaws, whereby said jaws and knives will open to release the wire while said handles are being squeezed.

4. The combination according to claim 3, said cam being secured to said movable clamp and pivoted to said first arm, said cam actuating element comprising a roller carried by said second arm and engageable with the cam.

5. The combination according to claim 4, said cam having a recess engageable by the roller during the first stage of squeezing movement, a raised arcuate portion engageable by the roller during the second stage, and another recess engageable by the roller at the end of the squeezing movement.

6. The combination according to claim 3, said means for drawing said knives away from said jaws comprising a pair of lugs on said other arm between which the bight of said spring is disposed.

7. The combination according to claim 1, said knives being formed at the end of a hairpin-shaped spring disposed between said clamps, and a spring connecting said arms and urging them to a position in which said hand grips are spread apart.

8. In a wire stripper, a pair of pivoted arms having squeezable hand grips, a fixed clamp and a movable clamp mounted on a first of said arms, a pair of jaws at the outer ends of said clamps movable between a spread-apart position and a position gripping a wire, a pair of knives inwardly of said jaws and movable from a retracted position to a position penetrating the insulative sheath of wire in response to said jaw movement, means responsive to a first stage of squeezing movement of said hand grips to move said jaws to their gripping position and said knives to their penetrating position, means responsive to a second stage of squeezing movement of said hand grips beyond said frist stage to move said knives axially away from said jaws to strip the insulative sheath from the wire, means responsive to a third stage of squeezing movement of said hand grips beyond said second stage and before release of said hand grips to cause said jaws and knives to move to their retracted positions, and means responsive to release of said hand grips for moving said knives axially back to their original positions while still retracted.

9. In a wire stripper, a pair of pivoted arms having squeezable hand grips, a fixed clamp and a movable clamp mounted on a first of said arms, a pair of jaws at the outer ends of said clamps movable between a spread-apart position and a position gripping a wire, a pair of knives inwardly of said jaws and movable from a retracted position to a position penetrating the insulative sheath of a wire in response to said jaw movement, means responsive to a first stage of squeezing movement of said hand grips to move said jaws to their gripping position and said knives to their penetrating position, means responsive to a second stage of squeezing movement of said hand grips beyond said first stage to move said knives axially away from said jaws to strip the insulative sheath from the wire, means responsive to a third stage of squeezing movement of said hand grips beyond said second stage to cause said jaws and knives to move to their retracted positions, and means responsive to release of said hand grips for moving said knives axially back to their original position while still retracted, said means mponsive to the squeezing movement comprising a cam on one of said arms a cam actuator on the other arm.

10. The combination according to claim 9, said cam being connected to said movable clamp and pivoted to said first arm, said cam actuator being on the second arm, the cam having a recess engageable by the cam actuator during said first stage of movement, an arcuate raised portion engageable by the cam actuator during the second stage of movement and a recess engageable by the cam actuator during the third stage of movement, and means urging said knives and jaws apart when the third stage of movement is reached.

11. The combination according to claim 10, said lastmentioned means comprising a hairpin-shaped spring disposed between said clamps, the knives being carried by the ends of said spring.

12. The combination according to claim 11, said means for moving the knives axially comprising a pair of lugs carried by the second arm and engageable with the bight of said spring.

13. The combination according to claim 8, said clamps being made of resilient steel whereby they will flex to accommodate difi'erent diameters of wires.

14. The combination according to claim 13, further provided with graduated markings on one of said clamps whereby the length of wire to be stripped may be predetermed.

# i i i 

1. A wire stripper comprising a pair of pivoted arms having hand grips at one end, a movable and a fixed clamp mounted on a first of said arms, means carried by said arms responsive to squeezing of said hand grips to move said movable clamp toward said fixed clamp, wire gripping jaws carried by the outer ends of said clamps, a pair of knives disposed inwardly of said jaws, said knives being movable in response to said clamp movement from a retracted position to a position penetrating the wire insulation, the degree to which the knives come together being a function of the spacing of said jaws when they grip the wire, said clamps being made of material which is sufficiently resilient to accommodate different wire diameters and being deformable in response to gripping of the wire insulation by said clamps and further squeezing of the hand grips.
 2. A wire stripper comprising a pair of pivoted arms having hand grips at one end, a movable and a fixed clamp mounted on a first of said arms, means carried by said arms responsive to squeezing of said hand grips to move said movable clamp toward said fixed clamp, wire gripping jaws carried by the outer ends of said clamps, a pair of knives disposed inwardly of said jaws, said knives being movable in response to said clamp movement from a retracted position to a position penetrating the wire insulation, the degree to which the knives come together being a function of the spacing of said jaws when they grip the wire, said clamps being made of material which is sufficiently resilient to accomodate different wire diameters, said means for moving the movable clamp comprising a cam carried by one of the arms and a cam actuating element carried by the other arm, said cam being shaped so that a first stage of squeezing movement of said hand grips will cause said movable clamp to move toward the fixed clamp, means on said second arm responsive to a second stage of squeezing movement to draw said knives away from said jaws, thereby stripping said insulation from the wire, said cam being so shaped that the jaws and knives will be prevented from opening during said second squeezing stage.
 3. The combination according to claim 2, said cam being so shaped that as said handles are squeezed beyond said second stage of movement said jaws will be released, said knives comprising the facing ends of a hairpin-shaped spring between said jaws, whereby said jaws and knives will open to release the wire while said handles are being squeezed.
 4. The combination according to claim 3, said cam being secured to said movable clamp and pivoted to said first arm, said cam actuating element comprising a roller carried by said second arm and engageable with the cam.
 5. The combination according to claim 4, said cam having a recess engageable by the roller during the first stage of squeezing movement, a raised arcuate portion engageable by the roller during the second stage, and another recess engageable by the roller at the end of the squeezing movement.
 6. The combination according to claim 3, said means for drawing said knives away from said jaws comprising a pair of lugs on said other arm between which the bight of said spring is disposed.
 7. The combination according to claim 1, said knives being formed at the end of a hairpin-shaped spring disposed between said clamps, and a spring connecting said arms and urging them to a position in which said hand grips are spread apart.
 8. In a wire stripper, a pair of pivoted arms having squeezable hand grips, a fixed clamp and a movable clamp mounted on a first of said arms, a pair of jaws at the outer ends of said clamps movable between a spread-apart position and a position gripping a wire, a pair of knives inwardly of said jaws and movable from a retracted position to a position penetrating the insulative sheath of wire in response to said jaw movement, means responsive to a first stage of squeezing movement of said hand grips to move said jaws to their gripping position and said knives to their penetrating position, means responsive to a second stage of squeezing movement of said hand grips beyond said frist stage to move said knives axially away from said jaws to strip the insulative sheath from the wire, means responsive to a third stage of squeezing movement of said hand grips beyond said second stage and before release of said hand grips to cause said jaws and knives to move to their retracted positions, and means responsive to release of said hand grips for moving said knives axially back to their original positions while still retracted.
 9. In a wire stripper, a pair of pivoted arms having squeezable hand grips, a fixed clamp and A movable clamp mounted on a first of said arms, a pair of jaws at the outer ends of said clamps movable between a spread-apart position and a position gripping a wire, a pair of knives inwardly of said jaws and movable from a retracted position to a position penetrating the insulative sheath of a wire in response to said jaw movement, means responsive to a first stage of squeezing movement of said hand grips to move said jaws to their gripping position and said knives to their penetrating position, means responsive to a second stage of squeezing movement of said hand grips beyond said first stage to move said knives axially away from said jaws to strip the insulative sheath from the wire, means responsive to a third stage of squeezing movement of said hand grips beyond said second stage to cause said jaws and knives to move to their retracted positions, and means responsive to release of said hand grips for moving said knives axially back to their original position while still retracted, said means responsive to the squeezing movement comprising a cam on one of said arms a cam actuator on the other arm.
 10. The combination according to claim 9, said cam being connected to said movable clamp and pivoted to said first arm, said cam actuator being on the second arm, the cam having a recess engageable by the cam actuator during said first stage of movement, an arcuate raised portion engageable by the cam actuator during the second stage of movement and a recess engageable by the cam actuator during the third stage of movement, and means urging said knives and jaws apart when the third stage of movement is reached.
 11. The combination according to claim 10, said last-mentioned means comprising a hairpin-shaped spring disposed between said clamps, the knives being carried by the ends of said spring.
 12. The combination according to claim 11, said means for moving the knives axially comprising a pair of lugs carried by the second arm and engageable with the bight of said spring.
 13. The combination according to claim 8, said clamps being made of resilient steel whereby they will flex to accommodate different diameters of wires.
 14. The combination according to claim 13, further provided with graduated markings on one of said clamps whereby the length of wire to be stripped may be predetermed. 